/* let a = 12;
console.log(a.toString());
console.log((NaN).toString()); */

// 字符串拼接
/* console.log('10' + 10);
console.log('10' - 10);
console.log('10px' - 10); */ // NaN

// let b = 10 + null + true + [] + undefined + '珠峰' + null + [] + 10 + false;
/*
10 + null => 10 + 0 = 10
11 + true => 10 + 1 = 11
11 + [] => "11" 空数组变为数字, 先要经历变为空字符串, 遇到字符串, 啥都别想了, 直接变为字符串拼接
"11" + undefined => 11undefined
*/
// console.log(b);

